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Products => Test Equipment => Topic started by: ornea on August 06, 2021, 09:32:05 pm

Title: Telstra Contact Fault Locator - How do they work (to test GPIB cables/connector)
Post by: ornea on August 06, 2021, 09:32:05 pm
When I was a boy ... we used these contact fault locators in Telstra (aka Telecom Aust) to determine if a coax connector was faulty. Each and every connector was tested by connecting to the Contact Fault Locator and tapping the connectors with a nylon hammer.  It was very good at finding suspect connectors.

Any suggestions on how such a device would work?  Theory of operation?

This is a follow on from a previous post about testing GPIB cables.  We made a jig where each conductor is snaked to the other.  However, all my tests seem to indicate that the cables are very good.  The tests include:-

1. Passing a range of currents thru the snaked cable in series with a 8-ohm speaker and tapping, wiggling and re-mating the connectors.  (The mating's are audible but once mated are silent)   

2. Passing a current thru the snaked cable and using a cro to scope the volt drop across the snaked cable  then tapping, wiggling and re-mating the connectors

All these tests indicate that the GPIB cables and connectors are rock solid.  And they may well be but I am suspicious.

So how to detect the smallest of current variations and amplify.  Any suggestions.  I think Mr Carlson's Lab has a design but maybe available to Patrons only.

Thanks for reading
Ornea